APA (7th ed.) Citation

Sinek, S. (2009). Start with why: How great leaders inspire everyone to take action. Penguin Group (USA) Inc..

Chicago Style (17th ed.) Citation

Sinek, Simon. Start with Why: How Great Leaders Inspire Everyone to Take Action. New York: Penguin Group (USA) Inc., 2009.

MLA (9th ed.) Citation

Sinek, Simon. Start with Why: How Great Leaders Inspire Everyone to Take Action. Penguin Group (USA) Inc., 2009.